Grinding machine



Jan. 13, 1970 PARRELLA ET AL 7 GRINDING MACHINE I Filed Oct. 18, 1966 2 Sheets-Sheet 1 Fig.1. 25

INVENT OR D4350 0M9 OR B Jan.13,197'0 AR E- ETVAL 3,488,887

GRINDING MACHIPIJE I 7 Filed Oct. 18, 1966 2 Sheets-Sheet 2 INVENTOR$ V @Ey FHFrcd T. PowveHa Qohn C. Hmdnchfic,

T i BY W60 Ms WW ATTORN S United States Patent GRINDING MACHINE Alfred T. Parrella, Newtown, and John C. Hinchcliffe,

Cheshire, Conn., assignors to Farrel Corporation, Ansonia, Conn.

Filed Oct. 18, 1966, Ser. No. 587,559 Int. Cl. B24b /04, 49/00, 51/00 US. CI. 51-49 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a grinding wheel retract mechanism on a grinding machine. Retract means, independent of any motion of the wheel head along a workpiece, is provided to retract the grinding wheel a fixed distance from the workpiece and then return the grinding wheel to the same position from which it was retracted.

This invention relates to grinding machines and more particularly relates to grinding machines of the type adapted to operate upon a generally cylindrical workpiece such as a calender or mill roll.

In the grinding or regrinding of calender rolls, the roll is suported at its journals on neck rests and rotated through means of a headstock drive. However, the center line or axis of the roll does not necessarily coincide with the axis of the headstock inasmuch as the roll is supported on the circumferential surfaces of the journals and not its rotative axis. The reason for this is that the rolls may be of such magnitude and weight that it is not possible to support the roll on its axis by means of chucks, center supports etc., which engage the roll at the center thereof.

Because of this means of rotatably supporting the roll, the axis of the roll cannot be definitely ascertained with respect to the axis of rotation of the headstock drive means. Accordingly, the carriage carrying the grinding wheel has no fixed relation from roll to roll with the axis of each roll,

Therefore, this lack of a definite dimension between the edge of the grinding wheel and the center of the roll when the roll is being ground presents the possibility of error in gaging the roll. Frequently during a grinding operation it' is desired to retract the grinding wheel from the roll in order to perform a gaging or measuring operation on the roll.

A problem is then presented in repositioning the roll in the exact position from which it was retracted prior to the gaging or measuring operation. It will be apparent that if the roll is moved too close in repositioning too much material will then be removed from the roll, resulting in wasted removal of material and requiring a regrinding operation, while if the grinding wheel is underrepositioned, that is, not as close as before, a ledge might then be defined or ground on the roll requiring further machine time to clean up.

Accordingly, the present invention provides a new and improved means for retracting a grinding wheel from a workpiece and then precisely repositioning the grinding wheel to the same position from which it was retracted. This is achieved in one form of the invention by providing a mechanism which has two stable positions of operation and which is effective upon actuation thereof to pivot or move the grinding wheel support a fixed distance either to retract such grinding wheel or to reposition such grinding wheel. The mechanism is further arranged so that it does not affect or introduce error in the operative positions of the grinding wheel during normal grinding or crowning operations.

An object of this invention is to provide a grinding machine which has new and improved means for retracting the grinding wheel a predetermined distance from a workpiece and then repositioning the grinding wheel in the same position from which it was retracted with respect to the workpiece.

Another object of this invention is to provide a new and improved mechanism for pivoting a grinding wheel and support therefor a fixed distance to retract it from a calender roll and then precisely reposition the grinding wheel to the position from which it was retracted.

A further object of this invention is to provide new and improved apparatus for retracting and repositioning the grinding Wheel of a roll grinding apparatus without affecting grinding infeed movement or position, or roll crowning movement or position of the grinding wheel.

The features of the invention which are believed to be novel are set forth with particularity and distinctly claimed in the concluding portion of this specification. The invention, however, both as to its organization and operation, together with further objects and advantages thereof, may best be appreciated by reference to the following detailed description taken in conjunction with the drawings in which:

FIG. 1 is a side elevation, shown partly in section, of a roll grinding machine embodying the invention;

FIG. 2 is a view seen in the plane of lines 22 of FIG. 1;

FIG. 3 is a sectional view seen in the plane of lines 3-3 of FIG. 2;

FIG. 4 is a sectional view seen in the plane of lines 4-4 of FIG. 3;

FIG. 5 is a sectional view seen in the plane of lines 5--5 of FIG. 3; and

FIG. 6 is a schematic diagram of a hydraulic actuating circuit.

In the drawings a grinding machine is generally indicated by the reference numeral 10 and comprises a base or bed 11 having a carriage 12 longitudinally movable along the length thereof on ways 13 and 14. A sub-base or sub-carriage 15 is movable on carriage 12 perpendicular to the movement of carriage 12 on bed 11 so that the carriage 15 and grinding wheel 16 carried thereon may advance and retract towards a workpiece such as a calender roll 17, shown in dotted line. Pivotally carried by sub-base 15 is a grinding wheel head 18 which is pivotal about a shaft 18a carried by sub-base 15 below the axis of the grinding wheel. Wheel head 18 rotatably carries a shaft 19 to which is mounted the grinding wheel 16. Shaft 19 has a pulley 20 thereon through which it is rotated by a motor 21, also having a pulley 22 on the shaft thereof with a belt 23 connecting pulleys 22 and 20.

In operation, the grinding wheel 16 is advanced toward the roll to form a grinding function by advancing carriage 15 at predetermined rates until a probe 24 which is biased to project 'beyond grinding wheel 16 engages the roll and actuates speed control mechanism to control the speed at which the grinding wheel approaches the roll. The probe 24, being movable with respect to the grinding wheel, actuates speed controlling elements (not shown) located within housing 25. For more specific details of the mechanism thus far described, reference may be had to Reissue Patent 25,794, assigned to the same assignec as the present invention.

The pivotal motion of wheelhead 18 on sub-base 15 is utilized to achieve very slow and precise approach of the grinding wheel 16 to roll 17 and thereafter to control the infeed when contact is made. Such pivoting or tilting is accomplished through a force producing mechanism which exerts a force on wheelhead 18 to cause it to pivot about shaft 18a. In one form the tilting force is exerted through a pair of levers 28 and 29. Lever 28 is pivotally attached at one end thereof to a travelling nut 30, movable on a lead screw 31 which is rotatably carried on wheelhead 18. Screw 31 may be rotated by means of a pulley 31a as hereinafter described. The opposite end of lever 28 is supported on a knife edge 32 or other suitable pivotal point carried by a projection 33 on sub-base 15. Lever 29 is pivotally connected to lever 28 intermediate the ends thereof by means of a shaft or pin 34 and bears on a knife edge 35 or other similar pivot point intermediate the ends thereof against a projection or reaction portion 36 of wheelhead 18. The free end of lever 29 carries a roller 37 which bears on a horizontal surface 38 which may form a portion of a force producing and reaction mechanism designed to impart pivotal movement to wheelhead 18.

When the wheel 16 is grinding upon the roll 17, the infeed or depth of cut being made may be detected by sensing the current of motor 22. The infeed may accordingly be regulated by moving the grinding wheel '16 toward or away from roll 17 upon detection of the motor current. This may be accomplished by rotating screw shaft 31. When screw 31 is rotated in such a manner that nut 30 moves downwardly, lever 28 will move in a counterclockwise direction about edge 32 and pivot pin 34 will then move in a downward direction. As lever 29 rotates counterclockwise about roller 37, it lowers the wheel and grinding wheelhead 18 will slowly pivot in a clockwise direction about shaft 18a which retracts wheel 16 from roll 17.

If screw shaft 30 is rotated such as to raise travelling nut 30 thereon, lever 28 will tend to rotate in a clock wise direction about edge 32 raising pivot point 34. This then applies an upwardly directed force to pivot 34 and lever 29 at that end as lever 29 is rotated in a clockwise direction. It may thus be seen that surface 38 in this mode of operation provides a reaction surface for in ducing pivoting or tilting of wheelhead 18.

Tilting of the grinding wheelhead 18 may also be accomplished by application of an upwardly directed force to surface 37 or downward movement of surface 38. If the roller 37 end of lever 29 is raised the lever will pivot counterclockwise about pin 34 and exert an upward tilting force on grinding wheelhead 18 through reaction portion 36 thereof. This will tilt wheel 16 toward roll 17 Conversely, if surface 38 is lowered, lever 29 will rotate in a clockwise direction and thus lower wheelhead 18 which retracts wheel 16 from roll 17.

This last described operation of levers 28 and 29 to effect approach and retraction of grinding wheel 16 may 9e utilized independently of lead screw 31 to achieve a :rowning operation on a calender roll. In such operation he grinding wheel is tilted into or from the grinding wheel in timed relation with movement of the carriage [2 along the length of bed 11 to produce a predetermined contour on the roll.

In the illustrated apparatus, the movement of carriage 12 on the bed 11 is sensed by means of a gear train which comprises a gear 40 engaging a rack 41 on bed 11, gears 12, 43, 44, 45, 46, 47, a worm 48 and wormwheel 49 which drive a cam 50. As cam 50 rotates a follower 51 in a platform member 52 providing surface 38 will move vertically thereby imparting upward movement to or al .owing downward movement of roller 37 and, hence, ever 29. Cam 52 has a variable axis of rotation which nay be predetermined by a hand crank or a motor 53 o predetermine the degree of crown to be imparted to roll 17.

This crowning mechanism is described in more detail .n the aforementioned Reissue Patent 25,794 and refer- :nce may be had thereto for the specific details of op- :ration. For further purposes of discussion platform nember 52 may be considered as a vertically movable lctuating device for supporting and moving wheelhead 18 with respect to shaft 18a.

In accordance with the invention, means are provided independent of the infeed or crowning for retracting grinding wheel 16 from roll 17, and thereafter returning the grinding wheel to the exact position it was in before such retraction.

The free end of lever 29 rotatably receives therein a shaft having an eccentric portion 61 (FIGS. 2 and 3). Roller 37 in the form of a bearing assembly having inner and outer races with bearing elements therebetween is mounted to eccentric portion 61. The inner race of bearing assembly 62 is non-rotatably mounted on eccentric portion 61. Bearing 62 rests on surface 38 of platform member 52 which is vertically movable in slides 63 and 64 on wheelhead 18. Roller 51 rides on the outer periphery of cam 50. End 65 of shaft 60 is keyed to a coupling 66 which coupling is also keyed to a shaft 67 of a torque producing device. The coupling 66 is housed within an adaptor member 68 which is secured to lever 29 as by means of bolts 69. Adaptor 68 also has mounted thereto a rotary piston 70 arranged to produce a torque on shaft 60. Shaft 60 is longitudinally affixed with respect to lever 29 by means of lock nuts 72 and 73. Also secured to lever 29 is a shaft motion limiting member comprising a housing 75 receiving therein a collar or sleeve 76 (FIGS. 3 and 5) which is keyed at 77. Sleeve 76 carries a cam key 78 in a longitudinal slot 79 defined therein. Housing 75 has a slot 80 defined therethrough which in turn defines abutment surfaces 81 and 82, which define the end points of rotary movement of shaft 60 when engaged by cam key 78.

Shaft 60 is rotated by means of the rotary piston 70. The rotary piston comprises a housing member 83 having ports 84 and 85 defined therein to permit entrance and exit of hydraulic fluid therefrom. A dividing vane 86 is positioned between the ports 84 and 85. Shaft 67 is supported centrally within housing 83 and has keyed thereto a collar or sleeve 88 having longitudinally extending vane 89 which together with vane 86 divides the interior of housing into two longitudinal sections. Such rotary pistons are commercially available items that may be obtained from several manufacturers. One source is the Ex-Cell-O Corporation, Greenville, Ohio, which markets these devices under the trademark ROTAC.

When fluid under pressure is introduced into port 84 vane 89 on sleeve 88 will rotate counterclockwise to the position shown in dotted line. This in turn will rotate shaft 60 through coupling 66 until cam key 78 abuts surface 82. At this time, shaft 60 will be in the position shown in FIG. 5 and eccentric 61 as in the position shown in FIG. 3. This will raise lever 29 in counterclockwise motion about shaft 33 and wheelhead 18 will be in a normal grinding position.

Now assume that it is desired to retract grinding wheel 16 from roll 17. Fluid is introduced into port 85 while it is exhausted from port 84. This will rotate vane 89 and sleeve 88 together with shaft 87 in a clockwise direction and through coupling 66 will rotate shaft 60 until cam key 78 moves to a position where it engages surface 81. Eccentric portion 61 of the shaft now rotates to a low point which moves lever 29 in a clockwise direction, causing grinding head 18 to move in a clockwise direction about shaft 19 and retract wheel 16 from roll 17. The distance of movement of grinding wheel 16 from the roll 17 is not critical. The movement need only be of sutficient distance to disengage the grinding wheel from roll 17 to allow a desired clearance and cessation of operation upon the roll. Now when it is desired to recommence the grinding operation, fluid is introduced into port 84 and exhausted from port 85. Vane 89 then moves back to the dotted line position to place shaft 60 in the position shown in FIG. 5, and reposition grinding wheel 16 exactly in the same position as before it was retracted. The grinding operation may then continue.

Rotary piston 70 is actuated through a hydraulic circuit as shown in FIG. 6 which comprises a source of hydraulic fluid 90, a pump 91, pressure relief valve 92, a four-way valve 93 controlled by solenoids 94 and 95. In operation, the pump is always operated to provide a hydraulic pressure of predetermined magnitude at fourway valve 93. The pressure is regulated by valve 92. A pressure indicating instrument 96 may be included. The solenoids 94 and 95 are energized and de-energized selec tively to either apply fluid under pressure to one of ports 84 or 85 and exhaust the fluid from the other port.

In this manner, it may be seen that the grinding wheel may be retracted from the workpiece 17 and after retraction exactly repositioned in the same relation as it had with the workpiece 17 as before being retracted. The de scribed apparatus provides a means of moving the grinding wheel of a roll grinding apparatus a predetermined distance from a grinding position and precisely repositioning the wheel without disturbing or interrupting wheel infeed or wheel crowning movement.

It may thus be seen that the objects of the invention set forth above as well as those made apparent from the preceding description are efficiently attained. While preferred embodiments of the invention have been set forth for purposes of disclosure, other embodiments of the invention as well as modifications to the disclosed embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments of the invention and modifications thereof which do not depart from the spirit and scope of the invention.

What is claimed is:

1. In roll grinding apparatus comprising means for rotatably supporting a roll to be ground, a bed, a carriage movable on the bed along the length of a supported roll, means for moving the carriage, a grinding wheel platform on said carriage, a grinding wheel carried on said platform, said platform being pivotally mounted to said carriage for movement toward and away from a roll, means on said carriage supporting said platform about said pivotal mounting; rotatable camming means disposed between said platform and said support means, means defining fixed limits of travel for said camming means, means independent of the means for moving the carriage for rotating said camming means between said fixed limits, said camming means upon rotation to one limit of travel being effective to pivot said platform in one direction through a fixed distance, and being effective upon rotation to the other limit of travel to return said platform through said fixed distance to the original position.

2. The apparatus of claim 1 wherein said support means on said carriage is vertically movable to impart pivotal movement to said platform.

3. The apparatus of claim 2 wherein said support means is moved in timed relation to movement of said platform along the length of a roll so as to impart a predetermined crowning motion to said grinding wheel.

4. The apparatus of claim 1 further including a first lever having one end thereof pivoted to said platform and the other end thereof supported on said carriage, a second lever having one end thereof pivota-lly connected to said first lever intermediate the ends thereof, the other end of said second lever being supported on said means on said carriage supporting said platform, and means intermediate the ends of said second lever supporting said platform thereon, said rotatable camming means being carried at said other end of said second lever.

5. The apparatus of claim 4 wherein said camming means comprises a shaft rotatably carried by said second lever at the end thereof, said shaft having an eccentric portion, a roller mounted to said eccentric portion, said roller supporting the end of said second shaft on said means on said carriage supporting said platform, stop means defining a predetermined angle for limiting rotation of said shaft in either direction, means for rotating said shaft.

6. The apparatus of claim 5 wherein said means for rotating is carried on said second lever.

7. The apparatus of claim 5 further including means for holding said shaft in the positions defined by said stop means.

8. In roll grinding apparatus having means for rotatably supporting a roll to be ground, a carriage movable along the length of the roll on said support means, a grinding wheel platform on said carriage, a grinding wheel carried on said platform, said platform being pivotally mounted to said carriage, a vertically movable member, 'said platform being further supported on said vertically movable member so that upon movement of said member pivotal motion is imparted to said platform, means for predetermining the position of said member to produce a desired position on said platform, rotatable camming means disposed between said member and said platform and having a predetermined angular rotation such that when said camming means is rotated in one direction it moves said platform in a clockwise direction and when rotated in the other direction it moves said platform in a counterclockwise direction, means defining stops determining the limits of travel of said camming means so that said platform with said grinding wheel thereon is moved a fixed distance from a grinding position upon rotation of said camming means in one direction and returned to the same grinding position upon rotation of said camming means in the other direction.

9. In a roll grinding apparatus comprising means for rotatably supporting a roll to be ground, a bed, a carriage movable on the bed along the length of a supported roll, means for moving the carriage along the bed, a grinding wheel platform on said carriage, said platform being movable toward and away from a supported roll, a grinding wheel on said platform; a rotatable driving member independent of the means for moving the carriage along the bed constructed and arranged to move said platform away from and toward the roll, spaced apart means, means positioned to engage said driving member and define fixed limits of rotation of said driving member in either direction of rotation, and power means for rotating said drive means between said spaced apart means and holding said drive means at one of said two limits.

10. The apparatus of claim 9 wherein said fixed limits of rotation are less than 360 apart.

References Cited UNITED STATES PATENTS 2,175,057 10/1939 Kearns 51-16502 3,070,925 1/1963 WOOdfOrd et a1 51-49 3,088,250 5/1963 Hold et a1 51-49 X 3,280,512 10/1966 Seidel 51165.02 3,333,370 8/1967 Parrella 5149 X FOREIGN PATENTS 290,942 5/ 1928 Great Britain.

JAMES L. JONES, IR., Primary Examiner US. Cl. X.R. 5 11 65 

